Characteristics of Sterilised Nickel Titanium and Stainless Steel Orthodontic Archwires

Sterilisation removes microorganisms in the vegetative or spore states from a material, surface or medium. Ensuring infection control is of utmost importance for health safety. Pathogenic microorganisms are frequently transmitted from one person to another because of ineffective sterilising agents, apparatus and equipment. The aim of this study is to investigate the effect of sterilisation methods on morphological parameters of super elastic nickel titanium (NiTi) and stainless steel (SS) orthodontic archwires. The archwires were sterilised using a variety of methods, including dry heat sterilisation (oven) at 160 degrees C for 1 h, steam heat sterilisation (autoclave) at 121 degrees C for 15 min and cold sterilisation (2% glutaraldehyde) at 10 h. After sterilisation, the wires were tested, and the morphological changes was determined through atomic force microscopy (AFM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The AFM and SEM results obtained before and after the sterilisation of the NiTi and SS orthodontic archwires did not show clear differences in the surface structure. No changes in the elemental composition of the NiTi and SS wires, and no new phase appeared according to the XRD results which support the use of archwire sterilisation procedures as part of the infection control treatment and are considered a suitable procedure related to the characterisation of the orthodontic archwires.